Measurement of Dielectric Properties of Low-Density Polyethylene Nanocomposites Using “Sub-Hertz” Dielectric Spectroscopy

Recently, many studies have been conducted on the dielectric properties of Low-Density Polyethylene (LDPE) nanocomposites and produced different results. However, the composition of LDPE polymer and boron nitride (BN) as nanofiller has neither been well understood nor producing a convenient result. Similarly, the dielectric spectroscopy measured at “sub–hertz” frequency has been of little interest among researchers since it is often influenced by “conduction-like” effect. This research identified the dielectric properties of LDPE nanocomposites filled with hexagonal boron nitride (h-BN) nanofillers by using dielectric spectroscopy technique. The dielectric loss and relative permittivity for three different filler concentrations were investigated under “sub-hertz” frequency ranges at room temperature. The cylindrical electrode with guard ring configuration was used to conduct the experiment, in accordance to the ASTM D150 standard. The results revealed that 5 wt% filled polymer has lower loss tangent and permittivity compared to the unfilled polymer, due to the strong interaction between nano-particle and the polymer. This strong interaction is believed to limit the movement of the polymer chain. The decrease in loss tangent also indicates lower quasi-DC at low frequency. However, further increase in the filler loading has recorded an increment in the value of permittivity and loss tangent. This higher effective permittivity is mainly due to the influence of the filler permittivity

Pemanfaatan Serbuk Gergaji sebagai Substitusi Bahan Bakar pada Proses Pembakaran - Kiln di Pabrik Semen dengan Pendekatan Life Cycle Assesment (Lca)

Cement production was a process that requires huge thermal energy and produces high greenhouse gas emissions. Co-processing or utilising alternative materials and alternative fuels for the combustion process in kiln was a solution to meet energy needs and reduce greenhouse gas emissions in the cement industry. This study aimed to analyze input, output, environmental impacts of cement production and calculate CO2-eq reduction from the system used alternative fuels on co-processing. The method used to determine differences and calculate CO2-eq reduction due to co-processing was life cycle assessment (LCA) and system approach. Based on the results of the LCA, the case 1 that used 100% coal energy required 3.50 GJ/ton-cement, 126 kWh/ton-cement, 2.19 L-diesel-oil/ton of cement and emited 0.84 ton-CO2-eq/ton-cement. Case 2 that had been substituted alternative fuels (saw dust) required 3.03 GJ per ton of cement, 118 kWh per ton of cement, 1.44 L diesel oil per ton of cement and emited 0.92 ton-CO2-eq per ton of cement. The results of global warming impact of case 2 was higher than case 1. The assumption of climate neutral made reduction global warming impact of case 2 by 14.65% and decrease CO2 emissions annually in plant by 71,601 tons CO2/year. This result show that utilization of saw dust as biomass of climate neutral can be applied as an input for overall company specific emissions calculation to meet government regulation

Effectiveness of Antibiotic Prophylaxis for Leptospirosis among Adults: A Systematic Review

Leptospirosis is one of the most widespread re-emerging zoonoses in the world. Malaysia is known to be an endemic country for human leptospirosis, with a case fatality rate of 2.11%, and an average annual incidence rate of 7.80 cases per 100,000 individuals. This systematic review is conducted to determine the effectiveness of antibiotic prophylaxis for leptospirosis among the adult populations who are highly at risk of getting infected. A systematic search was performed for the relevant titles, abstracts and keywords on PubMed, Scopus, Cochrane and Google Scholar from inception to November 2017 based on the PICO strategy; which returned 126 studies. Screening of abstracts had shortlisted 19 studies and data extraction was conducted for 8 studies which had been accepted after review of the full text. For the evaluation of antibiotics prophylaxis effectiveness against leptospirosis, only trials and cohort studies with risk ratio (RR) were selected. The articles were analyzed from the viewpoint of the dosage, adverse effects, study settings and effectiveness of the antibiotic prophylaxis. Using fixed effects model, pooled RR showed protective association between antibiotic prophylaxis use against the incidence of leptospirosis (RR = 0.31; 95% CI: 0.20, 0.48). Antibiotic prophylaxis for leptospirosis had been shown to be effective in preventing the incidence of the disease among high-risk populations and carries minimal adverse effects. It is recommended that the practice of antibiotic prophylaxis for leptospirosis is included in the standard protocol for leptospirosis prevention among people at high-risk, including disaster response teams and patrons of eco-sports tourism activities; with the drug of choice being doxycycline, either as a single 200 mg dose or weekly dose of 200 mg for the duration of exposure, based on the setting, duration of event and resources available

Use of a Combination of MRSS-ANP for Making an Innovative Landfill Siting Decision Model

Landfill siting is a complex, multicriteria decision-making problem that needs an extensive evaluation of environmental, social, land use, and operational criteria. Integration of a median ranked sample set (MRSS) and an analytic network process (ANP) has been implemented to rank the associated criteria and select a suitable landfill site. It minimizes the uncertainty and the subjectivity of human judgments. Four groups of experts with different backgrounds participated in this study, and each group contained four experts. The respondent preferences were ranked in a 4-by-4 matrix to obtain the judgment sets for the MRSS. These sets were subsequently analyzed using ANP to obtain the priorities in the landfill siting criteria. The results show that land topology and distance from surface water are the most influential factors, with priorities of 0.18 and 0.17, respectively. The proposed integrated model may become a promising tool for the environmental planners and decision makers

The Pediatric Allergy and Immunology Unit of Ain Shams University in times of SARS-CoV-2 pandemic: approach and challenges

The Pediatric Allergy and Immunology (PAI) Unit of Ain Shams University, founded in 1988 by Professor Yehia El-Gamal and currently headed by Professor Shereen Reda, is a tertiary referral center for pediatric allergy, primary immunodeficiency, and rheumatology patients in Egypt. It serves more than 1300 patients with different immunological disorders, with an outpatient and inpatient sections and investigational laboratory. With the widespread of the SARS-CoV-2 and its declaration as a "pandemic", and owing to the heterogeneity of the different disorders managed and followed up in the unit, several measures have been taken in order to provide the necessary services for the patients. This service should maintain a rational balance between the need to mitigate the virus spread and to provide the optimum care for those who get infected, when in the meantime keep their original disease morbidity and mortality to the minimum. These measures were taken by the members of the PAI unit with the help of the head management team of Children’s Hospital, Ain Shams University and were subjected to continuous modification based on the evolving situation, emerging information, problems faced and the availability of human and medical resources

Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: an experience from a cluster-randomized double-blinded vaccine trial [NCT00125047]

OBJECTIVE: To determine the safety and logistic feasibility of a mass immunization strategy outside the local immunization program in the pediatric population of urban squatter settlements in Karachi, Pakistan. METHODS: A cluster-randomized double blind preventive trial was launched in August 2003 in 60 geographic clusters covering 21,059 children ages 2 to 16 years. After consent was obtained from parents or guardians, eligible children were immunized parenterally at vaccination posts in each cluster with Vi polysaccharide or hepatitis A vaccine. Safety, logistics, and standards were monitored and documented. RESULTS: The vaccine coverage of the population was 74% and was higher in those under age 10 years. No life-threatening serious adverse events were reported. Adverse events occurred in less than 1% of all vaccine recipients and the main reactions reported were fever and local pain. The proportion of adverse events in Vi polysaccharide and hepatitis A recipients will not be known until the end of the trial when the code is broken. Throughout the vaccination campaign safe injection practices were maintained and the cold chain was not interrupted. Mass vaccination in slums had good acceptance. Because populations in such areas are highly mobile, settlement conditions could affect coverage. Systemic reactions were uncommon and local reactions were mild and transient. Close community involvement was pivotal for information dissemination and immunization coverage. CONCLUSION: This vaccine strategy described together with other information that will soon be available in the area (cost/effectiveness, vaccine delivery costs, etc) will make typhoid fever control become a reality in the near future

Multidrug-resistant and clonal dispersion of enterotoxigenic Escherichia coli from ready-to-eat meat products in Duhok province, Iraq

This research evaluated the effluent proportion of E. coli and ETEC in RTE meat products, characterized the isolated strains' clonal relatedness, and determined their antibiotic resistance. 130 RTE products were gathered from various restaurants and street fast food vendors in Duhok and Zakho Province. The Isolates of E. coli identified by culture methods were confirmed as ETEC by multiplex PCR of the identified virulence genes. ERIC-PCR was applied to establish the clonal relationships between strains. The disk diffusion method performed the susceptibility of antibiotics on the isolated ETEC. Out of 130 examined samples, 39 (30%) isolates of E. coli and 16 (12.3%) ETEC were detected. Pan-fried burgers were revealed to be the most frequent contaminated sample type, with both E. coli and ETEC 50% and 23.3%, respectively (P≤0.05). A high clonal dispersion (12 genotypes) was observed among the isolated ETEC strains. A strong genetic linkage was discovered between a few isolates retrieved from the same sample type and within the strains from the same geographic source area. A high antibiotic resistance rate was observed with total resistance to Amoxicillin/clavulanate, Clarithromycin, Doxycycline, Erythromycin, and Clindamycin. Isolates from burger samples showed a higher resistance rate when compared with the other sample types (P≤0.05). Multi-drug resistance was noticed in all ETEC isolates. RTE meat products sold in our area have a high rate of clonally heterogeneous carrying multi-drug resistant ETEC and may constitute a significant public health risk

Activated K-ras and INK4a/Arf Deficiency Cooperate During the Development of Pancreatic Cancer by Activation of Notch and NF-κB Signaling Pathways

BACKGROUND:Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the United States, suggesting that novel strategies for the prevention and treatment of PDAC are urgently needed. K-ras mutations are observed in >90% of pancreatic cancer, suggesting its role in the initiation and early developmental stages of PDAC. In order to gain mechanistic insight as to the role of mutated K-ras, several mouse models have been developed by targeting a conditionally mutated K-ras(G12D) for recapitulating PDAC. A significant co-operativity has been shown in tumor development and metastasis in a compound mouse model with activated K-ras and Ink4a/Arf deficiency. However, the molecular mechanism(s) by which K-ras and Ink4a/Arf deficiency contribute to PDAC has not been fully elucidated. METHODOLOGY/PRINCIPAL FINDINGS:To assess the molecular mechanism(s) that are involved in the development of PDAC in the compound transgenic mice with activated K-ras and Ink4a/Arf deficiency, we used multiple methods, such as Real-time RT-PCR, western blotting assay, immunohistochemistry, MTT assay, invasion, EMSA and ELISA. We found that the deletion of Ink4a/Arf in K-ras(G12D) expressing mice leads to PDAC, which is in part mediated through the activation of Notch and NF-κB signaling pathways. Moreover, we found down-regulation of miR-200 family, which could also play important roles in tumor development and progression of PDAC in the compound transgenic mice. CONCLUSIONS/SIGNIFICANCE:Our results suggest that the activation of Notch and NF-κB together with the loss of miR-200 family is mechanistically linked with the development and progression of PDAC in the compound K-ras(G12D) and Ink4a/Arf deficient transgenic mice